Melting Ice and Colors!

I've seen this activity a few places, but this ice and color lesson caught my attention on Pinterest last year.

I thought I'd share our experience with melting ice and colors and how we conducted the experiment. J had a great time, and he really directed the lesson. I was happy with how it turned out!

We tried to fill the ice cube trays with primary colors (red, blue, yellow) food coloring and then added the water, and it was a disaster. I rinsed out and started over. We filled our ice cube tray 1/2 full of water (to give us a little wiggle room putting into the freezer) and then added the primary food coloring drops (4 drops per cube). We stirred each color with its own spoon (so we didn't cross contaminate colors before we even started our experiment).

We froze the ice and then placed them into clear custard bowls. We put two ice cubes in each dish, making sure each of the colors mixed (yellow/blue, red/blue, red/yellow). J predicted/hypothesized what was going to happen in terms of colors using little note cards in front of each dish, using markers for his predictions of colors.

I particularly like the yellow, which didn't show up in the wide shot above (see close-up below). I also liked the purple heart and the orange pumpkin.

Now, let me warn you that cheap food coloring is hard to wash off of hands. Both J and I were dyed for a day or two (surprisingly, the clothes remained unscathed):

We let the ice sit through naptime and brought out the paint brushes to see if his hypotheses were correct. He was spot on with his predictions:

Now, J was thinking like a true scientist, "What if..." He wanted to know what would happen if he mixed all of the colors. He tried dipping his brush into all the colors and then painting, but that would just end up the color of the last color he dipped in. Grandma suggested doing dots of each color and spreading them around:

It made brown! However, J wasn't super satisfied or convinced. He wanted to combine all the colors into one big bowl.

He painted with it, and he ended up at the same solution: brown (see brown line above the red line, below)

I loved making this experiment our own, how simple it was, and how excited J got about experimentation.

Egg Maracas

We're approaching Easter. It's a good time to reiterate how much I hate eating just eggs, but I have no problem with using eggs for science experiments. Last year's experiments were fairly extensive, but I'll have some new ones to add this year.

The first one comes from an idea listed on Kiwi Crate's DIY website, Egg Maracas. I enjoyed the idea because somehow we end up with collections of these plastic eggs, and it feels so wasteful to just toss them.

Music is very science oriented. Sound, sound waves, pitch, tone, rhythm, etc all have their place in science. I never played a musical instrument, and I was banned from my elementary school chorus. I stuck to dance, which is deeply rooted in music, in particular rhythm and patterns.

Anyways, the basic maraca is easy to make. For each maraca, we used:
- A plastic egg
- Rice
- 2 matching plastic spoons (we collect these too)
- Masking tape (nothing fancy on our end)

What we did:
1. We filled the plastic eggs with rice. Since we had 3 eggs, we decided to use 3 different amounts of rice to see how that would affect the sound.
2. We taped the eggs shut since they seem to easily split open.
3. We placed the spoons so they cupped the egg and the handles met at the bottom. We needed two sets of hands, one to hold the spoons and the egg and one to tape.
4. While one person holds the spoons and egg in place, the other person tapes around the spoons and the egg (just once should be fine) and down where the handles meet.
5. We covered the whole thing (except Big J's maraca) with tape.
6. We decorated the tape with Sharpies (note that rubbing alcohol takes off Sharpie marker in case you have reservations about handing your little one a permanent marker). Crayola rubs off too easily when placed on masking tape.

Lil J, Big J, and my maracas (from L-R)

Science:
-Guess which egg has the most rice? You can weigh them or listen to the sound difference. A fuller egg should sound deeper.
- Play a "Simon" like rhythm game where you give a pattern of shakes and your kid repeats them. Get more complex as you go. Let your kid be the leader too.
- Use other items instead of rice. How do beans or pennies sound in your shaker?


**I apologize for the poor lighting and Craisins (and much more you don't see) on our kitchen floor. We were invaded by ants, so what's normally in our cupboards is sprawled on our counters, table, and floors. Good news was this experiment was able to be done in a very small space (and impromptu - right before bed).

Cereal box marble tracks

I saw this cereal box marble run post on Pinterest and thought it would be a great science learning toy with some slight modifications. It was a hit with my 3 year old on this rainy Saturday afternoon.

The original idea is super easy, but really you can't control the tracks within the box limits. I think being modifiable gives kids the opportunity to apply more scientific principles, mainly the transfer of energy.

Transfer of energy recap:
-Items that start above the ground have potential energy since they can potentially fall to the ground.
-Once the items start falling, they lose potential energy and gain kinetic energy (kinetic is a fancy term for motion).
-Once there's no more potential (ie. no place more to fall), ideally all of the energy is kinetic and will continue in motion until other forces act on it. Other forces can include things like friction or other obstacles.

Here's what I came up with while J was supposed to be napping:

Cereal box and toilet paper marble tracks

I took a cereal box, opened it to flatten it carefully. I stuck one of the longer/larger sides of the box out behind as a base of support. I then taped the other sides so the other longer/larger side sticks mostly up. I did slightly angle it back to make sure marbles don't fly off the front.

I then cut toilet paper tubes in half as the tracks and taped them to the box with painters' tape for the marble ramps. The good thing about painters' tape is that you can reposition it a few times without ruining the tape or the box, yet it's still strong enough to hold up the tubes and marbles, allowing you to modify your designs. Feel free to test your tracks as you build.

Then tape a small paper cup at the end of the track to catch the marbles. I put a cup on top too to hold the marbles before their release.

Here's J demonstrating how it works, one marble at a time.

Work with your younger kid to make the design. If you have an older kid, let them try their designs alone. Did your design work? If not, how can you modify it so the marble tracks so the marbles don't fly out?
---Think angles of the tracks it jumps to or having backboards.

How many marbles can you release at once? How many marbles make it in the cup from your initial release?

Do bouncy balls work in your track? How do they differ in your track from the marbles?

Does the shooter marble work on your track? If not, why do you think it acts differently than the littler marbles.

After my model track became boring, Big J and I worked with Little J to make his own track. He made his turn around the box (a challenge, for sure!)

If you think your box design is ugly brown, feel free to decorate it with paint and markers.

Happy marble tracking :-)

Balloon Racers

I've been meaning to play with quick and easy materials to find a fun balloon racer to make at home.

Here's what I came up with:

Strawberry containers:

Benefits:

• Many holes = less work for me!
• Basket for the balloon to sit in/attach to easily (I attached it with a rubber band using a girth hitch knot).
• The basket can also carry weights if you chose some of the variation activities.

Cons:

• Lightweight, easily flips over.

Salsa containers (wheels):

Benefits:

• Due to my lack of motivation for cooking and the easiness of a nearby take-out Mexican fast food chain, we have PLENTY of these around the house.
• They are round-ish and bigger than bottle caps.

Cons:

• Hard to poke holes into (cheap plastic).  We tried to drill, ended up with a gentle poke of an awl.

*We used wooden skewers as axles and attached the salsa cups via press fit (you could glue them into place too).

Balloon and straw:

• I used a standard size birthday balloon.
• I attached the balloon to a cheap, standard bendy straw with a rubber band.
• Be careful not to squish the straw with the rubber band being too tight.

Here's how my balloon racer runs:

Variations:

• Try different sized balloons.
• Try attaching it to different size straws (vary diameter and length).
• Add weights (easy with a strawberry basket).
• Try to see if your racer runs on different surfaces (tile, carpet, sidewalk, asphalt).
• Use different materials.  You'd be surprised at what you can make from your recyclables collection.
• Steer your vehicle by placing the straw at different locations/angles and see what happens.

Here's what happens with a bigger straw and our basket:

Why?  The straw wasn't connected straight (hence the crazy sideways motion) and the forces from the straw were so great that the light basket just flipped over!

Lessons learned:

• Newton's third law: for every action, there's an equal and opposite reaction

J's Quote:

• I used making a cool science balloon race car as a bribe for him eating his dinner.  He held me responsible.
• (Passing me the strawberry basket that's been on our counter for a week) "Mommy, let's do science!"
• We got so excited about science that we forgot about dessert.

Homemade Squeeze Rocket Launchers

Tada - homemade squeeze rocket launcher:

Materials:
Small water bottle
Small straw (comes in a pack of 50-100 for ~$1 in most grocery stores)
Bigger straw (recycled from a McD's soda)
Small sticker

Launcher Assembly:
*Drill a hole, with similar size diameter as your straw, into the cap of the water bottle.
*Cut the small straw down to ~3 inches.
*Insert straw into newly made hole.
*Glue the straw into place (optional).

Rockets:
*Various size straws closed off completely on one end with a small sticker. (You can vary length/diameter, but the diameter of the rocket needs to be large enough to easily come off of the smaller straw with a squeeze of the bottle).
*Nerf-ish rockets (these too are fairly cheap - we found a pack at Fry's around Christmas that we've been using with our other rocket launchers too).

Notes:
*The launcher works better with one quick hard squeeze.
*Plastic water bottles are poor quality plastic and deform really easily.
*You can blow into the straw to quickly reform the bottle (demonstrated in video below).
*I don't recommend gluing the cap onto the bottle since you might want to stick a long skinny to recover the bottle shape.
*Ultimately it takes 2 minutes to put together, so it's not worth getting frustrated over the bottle.

Variations:
*Alter the length and diameters of the straw rockets being launched.  Note the differences between the rockets.
*Decorate the straws being launched.
*Give the straws fins and wings.  How does that change the flight of the rocket?
*Aim for a target.
*How high can you launch the rocket to the sky?

Here's a video of Big and Little J launching the rockets.  It's hard to capture the flight of the rocket.  The first launch was the Nerf-like rocket and the second was the straw:

Sail Cars with 2-3 yr olds

I did it! I had my first official Pepsi Refresh sponsored visit to a preschool!

I started with double this amount of special race cars!  Note-to-self, when speaking to 2-3 year olds, when you say you have a "special treat" for them, they think something yummy, not super cool race cars.  Whoops.

I started out with an introduction to the concept of gravity. We dropped some balls from way up high. They were able to guess that the balls will fall to the ground. Great hypothesizing! We talked about gravity keeping us on the ground and not letting us float up into the sky.  They happily repeated, "Gravity!"

I then thought it would be fun to see what they thought about what an untied balloon would do when dropped. Whoa! It didn't fall to the ground. It shot off like a rocket!  The kids giggled.  I then show them my balloon I have tied off and asked what they thought it would do if I let go.  They said go up to the sky.  However, it was just blown up with air and not helium, so it too dropped to the ground.  It was fun to see their wheels turning and get them making some educational guesses.

Ok, back to the non-edible "special treats".  I had pre-made the 18 vehicles the week before.  I hot-glued the wheels and only two kids' wheels fell off, one of the two was more interested in destruction than science.  It's all good - I'll count it as reverse engineering for now - still science.

We started with discussing what would happen if we let go of the cars on the ramps.  I had ramps of different sizes all across the room and tried to snap some pictures.  Man, these kids move quickly.  They quickly realize that the biggest ramp, held up by a bookshelf, was the best ramp for the fastest car!  Yay, they used their scientific process to figure that out because I didn't say.  The biggest ramp was the most popular by far.

On your marks, get set, go!

It was during the time we were playing with ramps that some teachers and kids from the older preschool rooms decided to peek in at our fun!  It looks like I might have to repeat this experiment with the 3-5 year olds too.  I don't mind.  It was tons of fun!

Back to the lesson: I then showed them that even when the cars aren't up high we can make them go.  I gave them all a sail (which I white-school-glued the night before and they all stayed together!) to put in their pre-punctured hole in the top of their car.  They tried it on the carpet first (which worked pretty well with the school-style, high traffic carpet)

A friend successfully moves his sail car 

This is another point where I love teaching science.  The 2-3 year old kids figured out the sail cars work better on the table than the carpet.  The whole experimented shifted to the tables.

Blowing on it like a candle

A race!

It's not working so well blowing down there

Yay, success!

Then they found out how to have real fun, blowing it off of the table!

And there it goes!

That was the basically the end of the lesson.  I let them have a few more minutes of free play with their science cars before I packed up the ramps.  This is the point where I could brainstorm about how to tweak the lesson for the next time.  They went back to the larger ramp, of course, but they wanted to make it taller.  It became taller and taller until it was basically vertical.  Then their cars were nose-diving into the ground!  I love letting kids experiment freely.  They thought it was pretty fun.

Try 1

Try 2

Almost captured the car mid-drop

Time for lesson - 10 minute set-up, 20 minute lesson!  I consider it a major success.  Keeping 2-3 year old kids' attention for 10 minutes is hard, and I had them most of the 20 minutes.  The kids all seemed to enjoy themselves and some kids wanted their parents to wait a little longer so they can finish their experiment (I did this in the late afternoon/pick-up time).

Lessons learned - don't use anything as ramps that would be of value.  Luckily, the ramps were recyclable cardboard and particle board scraps.  Thicker poster board would work well too.

I'm definitely pocketing sail cars for a future family science day.  Now to start thinking about the next lesson...

Related Post:

• How to make toilet paper tube sail cars

Toilet Paper Tube Sail Cars

My previous post on sail cars made it onto Pinterest (edited: I'm now on Pinterest!).  I feel so crafty though it was such a clunky car.  It was a really simple car to make on the fly and could be made out of things lying around the house (ie. a contact sol'n box).  It can also occupy kids' attention for some time.

I've been debating about my next lesson with the preschoolers at J's school.  I really want to do sail cars, but I'd have to make 12-15 of them (and make them look identical so we don't have 15 grumpy 2-3 yr olds).  The little voice in my head kept saying cafeteria milk cartons, but they aren't easy to come by if you don't have older kids in school.  I thought about it some more and played with what we had lying around the house.  Enter in my new sail car made from recycled materials that are plentiful: toilet paper tubes and empty tissue boxes.

I actually think this one works much better than the quick sail car I threw together in October.

Materials:

Toilet paper tube (or paper towel tube cut in 1/2 or 1/3)

Empty tissue box

Wooden dowel (I use skewer sticks with the tips cut off)

Popsicle stick (preferably a clean craft stick)

Scissors

Masking tape

Methods:

-Trace a circular object onto the tissue box cardboard (4 times) for the wheels***

-Cut out the 4 wheels

-Cut the two dowels 1/2 to 1 inch more than the diameter of the paper tube.

-Attach one wheel to each dowel (I press fit then masking tape it in place to the dowel) - make sure the wheels are straight.

-Single hole punch 4 holes for the axles - 2 in the front and 2 in the back (make the holes relatively straight across from each other and the front in line with the back holes).

-Insert wooden dowels in the holes and attach the other wheels (masking taping the wheels to the dowels if you so choose).

*Now you should have a car you can push around (even blow on the front of the tube to get it to move).  Test it to make sure your wheels are straight and the tube isn't touching the wheels.  You can also build a small cardboard ramp to let gravity drive the car.

Methods (cont):

-Cut out a sail shape from the tissue box.

-Attach sail to a popsicle stick via masking tape (tape front and back of sail to the popsicle stick).

-Carefully puncture the top of the tube with one pointy side of an opened pair of scissors.  I prefer the puncture to be perpendicular (90 deg) to the length. With only the top of the tube punctured, the sail won't be dragging on the floor slowing the car down.

-This new puncture should be just the right size to insert a popsicle stick.

-Reinforce mast with masking tape.

*Now blow on the sail and watch the car effortless glide across smooth surfaces (it still doesn't work well on carpet).

More fun activities with sail cars:

• Put your car on a long coffee table.  Can you give it enough power to drive over the edge?
• Navigate an obstacle course.
• Have a friend stand on the opposite side of the table.  Blow on opposite sides of the sail.  Watch the car go back and forth between you two.  Have a competition on who can get the car to fall off first.

***I used a compass this time around for wheel drawing, which was nice since I had a pin prick where the center of the circle was.  In turn, my wheels seem to turn better this time time than last when I think I used playdough containers as my circle guide.  Yay for being a little bit of a hoarder when it comes to old math tools.  I don't think I've used it since high school.

Related Posts:

• Sail cars with 2-3 yr olds 
• Sail cars out of a paper box 
• Balloon racers

Cookies

It's "C week" at J's preschool, and today was first lab meeting of the school year for me.  I wanted treats for the new faces to think we're lots of fun (which we are).  Not only are cookies are a great way to make friends, they are a great way to do (and eat) science.  There's measuring, mixing, chemical reactions, heat transfer, fractions, etc.  If you want to double the recipe, now you've added multiplication!!

J helped me make chocolate chip cookies for my lab yesterday.  This is our fave recipe which we got from a Ghirardelli bag of chocolate chip cookies many moons ago.  The key is 2 tsp of vanilla = delicious!

Ingredients:

1 cup of butter (2 sticks)                   2 ¼ cups flour

¾ cup sugar                                        1 tsp baking soda

¾ cup brown sugar (packed)             ½ tsp salt

2 eggs                                                1 package of chocolate chips (12 oz - or about 2 cups)

2 tsp vanilla

Directions:

• Combine butter, sugar, and brown sugar until light and creamy
• Add vanilla and eggs one at a time
• In a separate bowl, combine the flour, baking soda, and salt
• Stir the flour mixture slowly into the sugar mixture
• Slowly add the chocolate chips
• Drop cookie dough on cookie sheet (in desired amounts)
• Bake at 375°F for ~ 8 minutes (watch carefully - we like them slightly under baked so they are softer longer)
• Let cool and devour

Recipe makes ~4 dozen decent sized cookies

Variation: scoop dough into personal pan, bake 11 minutes, top with ice cream and enjoy your pizza cookie.  The pan is extremely hot and not recommended for little ones.  Please remove cookie from pan or cool before serving to little kids.

After I decided that our cookies last night were going to my lab, I asked J what he wanted to bring for "sharing time" this week.  They are supposed to bring something that starts with the letter c.  Bet you can't guess what his answer was.  The Cookie Monster would be so proud.

We went with another recipe, just for variety.  This is my next favorite recipe we found on a Funfetti box moons ago.

Funfetti Cookies
1 box Funfetti Cake mix - yes, it has to be Pillsbury - the other rainbow cake mixes smell like playdough when you make them into cookie dough and just don't taste right.
1/3 cup vegetable oil
2 eggs

Preheat oven to 350 deg F.  Mix ingredients in a bowl.  Scoop cookies out onto cookie sheet.  Bake for 7 minutes (again a little on the under baked side).  Makes 2 dozen Funfetti cookies.

*Cake cookies work really well for quickie desserts.  The general rule is follow the ingredients on the cake box (any brand cake), without the water and minus an egg.  Our next favorite is chocolate cake with chocolate chips added.  We're real dessert people if you can't tell.

Happy cooking!

Noise - sound and frequency

J loved banging on things from a young age.

This picture was actually taken the first time he decided to sit up on his own - when we put a pot in front of him and gave him a wooden spoon. He was a very content baby. The next few weeks - well, ok, the next year and a half - were spent trying out different sound wave formations by banging on anything we'd let him.

Things to try:
* Different objects doing the banging: sticks of various sizes, lengths and diameters, wooden spoons vs. metal spoons, water bottles full of water vs. rice.
* Banging on different objects: floor, walls, pots and pans of various sizes, some unbreakable toys that could get beaten up a little bit, play or real drums.
* Beat fast!!  Beat slow.  Can you repeat a rhythm?  Put on music and tap out some beats.

Remember to set boundaries.  Don't let your kid bang on or with anything valuable or breakable.

I'm going to recommend this experiment for the babies, just for sanity purposes.  Toddlers + banging = bigger headache!

Magnets

Magnets produce a special field that excites material containing iron (steel is a common material containing iron). When excited, the material wants to stick to the magnet. Or - the magnet sticks to the material (ie. the fridge - good luck moving the massive fridge with the very small magnet).

For this experiment, take a magnet (preferably a free one from restaurant advertisements) and go on a hunt to find where the magnet sticks!

Or just make it stick wherever...

Aw man, that didn't work.

Make sure you record your findings! Any surprising places? The fridge is a given, but my favorite is the dishwasher. What do your findings tell you about the material of those items?

If you get a stronger magnet, you can see what the magnet picks up. Use your imagination for picking out items (think office supplies, tools, stuff with steel). If some of your selections don't work, that's part of the learning process. Make sure your kid knows that some things didn't work and they are of a different material that doesn't have magnetic properties (ie. plastics, ceramics, etc.).

Sound Amplification

J loves hearing his voice and playing with tubes.

Why is your voice louder when you speak through a tube?
*The tube focuses the sound waves in one direction rather than the sound waves bouncing around the room before they hit your ear (my interpretation from the many websites explaining this concept to kids).
*This explanation is simple enough for kids.  However, there's a whole division of engineering focused on acoustics.  I also know how fun fluid dynamics could be, and so, I'm sure it's way more complicated than just "focusing the sound waves."  I just don't want mean comments.

Anyways, there's a lot that you can do with experimenting with tubes and sound!

What to try at home with your scientist:
*Speak into tubes of various sizes in length: toilet paper tube, paper towel tube, wrapping paper tube.
*Speak into tubes of various materials: paper towel tube, PVC pipe, plastic hosing.
*Speak into tubes of various diameters: PVC pipe would be good for this.  They sell it in varying diameters, and it's super cheap.  Or, maybe you have some lying around from various projects.
*Whisper, talk normally, talk loudly, sing songs, have fun!

Which makes the best amplification sound?
*I'm not telling.  Guess you'll have to experiment.

And for all you Mommies who need a muffler for your kid, Grief Speaks has just the solution: a scream box!**


**Again, we have yet to try this out.  I don't want to suggest anything that could make J squeal louder than he already does.  We're working on inside voices.  Maybe one day we'll try it, but he'll have to use it only outside (even if it muffles his scream).

Outdoor Rainy Day Science Fun

We're experiencing our winter here.  We're getting a little antsy though since we haven't been able to play outside much this week.  In anticipation of this latest storm, I bought J boots (really, I was hoping the storm would pass us buy since I bought the boots).

If you're willing to get wet, here are some fun outdoor rainy day science experiments.

Puddle Jumping:

How high can you jump?
Can you get the water to splash sideways?
How many waves can you make and count with one splash?
How many puddles can you jump in during 60 seconds?

Dada and J jumping high!

Drop an object into a puddle:

What happened to the water after the object dropped?
How long did it take the water to calm?

Floating objects (in puddles - stay away from flowing water):

What objects make good boats?  Think recyclables!!
Can you make your boat move?  How can you move the boat without your hands?  Without stomping next to it?  Can you direct the boat through an obstacle course?
How many "passengers" can your boat hold?

Measuring:

Find a stick.  Start sticking the stick in puddles and marking the water level of that puddle on the stick.  Which puddle has the deepest water (note it might not be the puddle with the largest area)?

We used J as a measuring stick.  Deepest puddle found!

Put a cup outside at the beginning of the storm and bring it in once the storm is over.  Measure how much water fell in the cup.  Put it in terms that your child can understand (since I'm sure a few inches or cups won't mean a lot to them right now though use the terms to get them used to comparisons).  Think, "1 inch of rain fell into our cup.  That's enough to fill your cereal bowl."  or "What container do you think will hold this amount of water?"  How long does it take the water to disappear from the rain catching container?

Other people's suggestions for sciency rain fun:
TLC suggests looking for bugs that come out when it rains and looking at the material properties of the leaves.  Compare dry and wet leaves or compare leaves from different trees.
Grandparents.com suggests painting with raindrops and powdered tempera paint (colors are physics!).
Squidoo suggests playing the lava game with puddles.  How can you get from point A to point B only by hopping in puddles.


If you're kid is like mine, he'll be having so much fun that he won't want to come inside (even if he's freezing cold).

Box Fun

Lately, I've been turning to boxes to help keep my sanity. You can do a lot with boxes. Since this is supposed to be science based, I'm going to convince you boxes are scientific.

First, let's talk shape. Kids are pretty good at identifying shapes. This is a good one for any age!

What type of objects fit in a box?
Can you fit different boxes within boxes? Who needs nesting toys when packaging is so plentiful?
How many different things can you pack into a box? Include baby, and trust me, baby will have fun helping you take everything back out (and putting it back in again!)!  I live for the giggles that occur when babies are having scientific fun!

Then, there's make believe fun! You can make boxes into just about anything using your imagination. I won't go into too much detail, but I am convinced that boxes are great inexpensive structural engineering materials for kids.  I'm sure if you use your imagination, you can justify making castles, forts, kitchen sets, cars, trains, etc. for "science".

J driving his car at 6 months!

Next, let's talk trajectories (yes, this is me getting giddy). Yay, physics! I was helping J clean up his toys, but I was being lazy and didn't want to get up. J pulled down his toy bin, and I threw a ball into the bin (now, I'm really not that sporty or coordinated). I didn't think anything of it until J squealed with delight. Then we played a little basketball, but Mommy mixed it up a little.

For background purposed: trajectories need a vertical and a horizontal component. You can hit the same target through multiple trajectory paths.  Show that you can throw the ball multiple ways and still (hopefully) make a basket.

Can you throw it a ball up high and still make it in the box?
If you miss, how can you change your throw to try again?
How far away can you stand and still make it into the box?
How hard can you throw? (Maybe, try that one outside)
What happens when you switch balls/throwing materials? Maybe put a lot of force into a lighter Nerf type ball, but it won't go as far as as a solid ball. Why is that?
Can you put a spin to the ball?  How does that affect your basket making capabilities?
Color different boxes (wrapping paper, construction paper, tempera paint) and have your kid throw into a specific box color. If you're super creative or have a lot of time on your hands (I'm envious), make cute bean bag toss targets (like a clown with an open mouth - or something that won't scare your kid).
Time your games.  How many balls can you make into the basket in a given time?  How long does it take you to make all of your balls into the basket?  Can you beat your high score?

Most of all, have fun!  This started out as what I thought would be a one time thing, but J loves playing makeshift basketball now (as you can see from the pictures above, we haven't moved far from the target yet).  Let me know how your games go and any other suggestions to add to why and how boxes are scientific.